Seal



United States Patent lnventor Foster M. Hagmann Los Angeles, CaliforniaAppl. No. 724,469 Filed April 26, 1968 Patented Nov. 24, 1970 AssigneesSusan S. Monselle,

a part interest, Amanda D. Lang, a part interest, Marlene A. Hagmann, apart interest, and Waldron A. Easton, a part interest SEAL 17 Claims, 7Drawing Figs.

U.S. Cl. 277/211, 277/180, 277/235, 285/363 lnt.Cl F16j 15/02 Field ofSearch 277/208- References Cited UNITED STATES PATENTS 2/1932 Oven277/235BUX Primary Examiner-Laverne D. Geiger Assistant ExaminerJeffreyS. Mednick Attorney-Fulwider, Patton, Rieber, Lee & Utecht ABSTRACT: Aseal embodying a ringlike retainer with, in cross section, a central weband resistibly deformable ridges at the inner and outer peripheries ofthe web. The retainer defines a pair of opposite1y facing grooves thatreceive in confining relationship a pair of deformable sealing elements.The volumes of the elements are initially less than the voids of theirrespective grooves and the resistance to deformation of the elements isless than that ofthe ridges. During seal installation, the ridges areflattened out under pressure and the voids of the grooves areprogressively reduced until they are substantially equal to the volumesof their respective elements, and the elements are forcefully urged intosealing contact with the faces of the parts.

v SEAL BACKGROUND or THE INVENTION This application relates to a sealand, more particularly, to an improved seal of the type adapted forsealing the interface between mating p'arts.

In the past, various types of seals have been used in applica tionswhere it is desired to seal the interface between mating parts. One typeof seal has a groove in one of the parts that receives a separatelyformed O-ring. The O-ring seal is subject to many significantdisadvantages. To begin with, in order to achieve sealing, it isnecessary to control the volumetric relationship between that of theO-ring and the void of the groove. Even if this is done, problems occurbecause of normal manufacturing tolerances. Possible toleranceconditions, e.g., an oversize groove and an underside O-ring, may resultin such a disparity between the .volume of the O-ring and the void ofthe groove that effective sealing cannot be achieved. A characteristicof O-ring sealing is that it depends upon the resilience or memory ofthe O-ring. If thisr'esilience is lost, as will occur after a period ofuse, the seal fails.

Even if satisfactory sea-ling can be achieved with'an O-ring, expensivemachining operations, closely controlled inspection techniques and otherinherently expensive manufacturing procedures are required. The resultis that the cost of the seal is relatively high.

Another more satisfactory method of sealing has involved molding rubbersealing elements in place in a grooved retainer member. While this makesit possible to overcome the adverse tolerance condition inherent inO-ring sealing and affords other advantages, it still'involvesrelatively costly manufacturing procedures.

In an effort to cut costs, various attempts have been made in the pastto use flat gaskets formed of plastics, or the like. These materialshave particular advantage in'sealing in that they are noncorrosive andnoncontaminating, as well as impermeable to most all liquids and gases.Many of these materials also are readily deformable so that they arecapable of conforming to surface irregularities in the parts to besealed.

Needless to say, a flat'gasket is much less expensive than seals of thetypes previously described, which have retainers with machined grooves.Notwithstanding these significant advantages, it has not been possibleto use these materials in a flat gasket seal because of their tendencyto extrude or cold flow when'subjected. to pressure. As force is appliedto bring mating flanges together, a gasket formed of these plastics willshift laterally or cold flow, thus precluding effective sealing frombeing achieved. Because of the nature of a flat gasket seal, the entireload imposed by the mating flanges is carried by the gasket. Even ifscaling is achieved initially, cold flow will continueover aperiod oftime, so that the seal will eventually fail. Moreover, in time, thematerial, like that of an O- ring, will take a permanent set or lose itsresiliency. Thus, any ability it may have had to respond to flangeseparation is lost.

SUMMARYOF THE'INVENTION The present invention provides a ringlikeretainer member having, in cross section, a central web and resistiblydeformable ridges at the inner and outer peripheries of the web. Thesemeans forming ridges define the boundaries of a continuousseal-confining groove. Disposed within the groove is a sealing elementformed of a deformable sealing material, preferably a resilientdeformable rubber or plastic. To insure that the ridges serve to confinethe sealing element within its groove, the. resistance to deformation orflattening of the ridges is made greater than that of the element.

The volume of the'sealing element is initially somewhat less than thevoid in the groove. With this arrangement, as closing force is applied,the ridges resistible flatten out, thereby reducing the effective voidof the groove until it substantially equals the volume of the sealingelement. When this condition is achieved, maximum sealing pressure isexerted, since sealing materials such as plastics and rubbers areincompressible.

In the illustrative embodiment, the retainer member is shaped to definea pair of seal-confining grooves in back-toback relationship and bandsof the elements are disposed in such relationship within their grooves.This enables sealing to be achieved against both faces of mating parts.The seal of the invention is especially adapted for use in this type ofapplica tion.

It is preferred that the ridges be configurated so as to have at leastsome spring-back capability when they are flattened out duringinstallation. Use of a retainer member with such ridges enables the sealto respond to separation of the mating parts, as is often encountered inpractice, and still maintain effective sealing.

DESCRIPTION OF THE DRAWING These and other objects, features, andadvantages of the invention will be better understood by referring tothe following detailed description, taken in conjunction with theaccompanying drawing in which:

FIG. 1 is a perspective view of a seal constructed in accordance withthe invention, a portion being broken away and removed to show thecross-sectional configuration;

FIG. 2 is a sectional view on an enlarged scale of the part shown inFIG. 1;

FIG. 3 is a sectional view, similar to FIG. 2, illustrating the sealpartially installed between opposing flanges;

FIG. 4 is a view similar to FIG. 3, except that full closing force hasbeen applied to the flanges;

FIG. 5 illustrates in section another embodiment of the seal of theinvention;

FIG. 6 illustrates in section still another embodiment; and

FIG. 7 is a sectional view, similar to FIG. 4, showing the seal of FIG.6 fully installed.

DESCRIPTION OF PREFERRED EMBODIMENTS accordance with the invention. Itmay be seen to include a metal retainer 12 and a pair of deformablesealing elements 14a and b mounted on the retainer in back-to-backrelationship.

The retainer 12 is integrally formed of a malleable material, such assheet metal, which is capable of being configurated into the desiredshape. As may be seen in FIG. 2, the retainer 12 has, in cross section,a central annular web 16 with resiliently deformable and generallytear-shaped ridges 18 and 20 at its inner and outer peripheries,respectively. In order to enable the ridges to deform or flatten outduring seal installation, the ridges have a vertical thickness, i.e., ina direction perpendicular to the plane of the web 16, greater than thethickness of the web itself. The ridges 18 and 20 cooperate with the web16 to define oppositely facing grooves 22a and b. The void of each ofthe grooves 22a and b is considered to be the space (area incrosssection) above or below the planes of the respective reference lines 24aand b in FIG. 2.

For optimum results, it is desired that the ridges l8 and 20 have somespring-back capability. Use of a resilient, flexible material, such assheet metal, to form the retainer 12 affords this advantage.

In order that the grooves 220 and b be of approximately the same depth,each of the ridges l8 and 20 is formed by a first section 26 that isstepped slightly downwardly from the web. The section 26 in turn joins,in series, a downwardly sloping section 28, an arcuate section 30 thatturns back toward the web 16, a downwardly sloping section 32 and,finally, a terminal section 34 that seats in flush-face engagement withthe section 26. Thus, the sheetmetal forms a loop along each edge of theweb, offset in both directions from the plane of the web.

The sealing elements 14a and b here comprise continuous, annular flatbands of deformable sealing material disposed within the grooves 22a andb and, for convenience of handling, attached to the opposite sides ofthe web 16. The resistance to deformation of the sealing elements isless than that of the ridges. Preferably the elements are formed of aresilient, deformable plastic or rubber of the types which have knownadvantages in sealing applications. It is desired that the material benoncorrosive and noncontamina ting and, in some applications, capable ofwithstanding high temperatures. Examples of materials which may provehighly satisfactory, depending upon the application, are the classes ofplastics known as vinyl polymers and copolymers, urethanes, olefins andcertain epoxy resins, and rubbers.

As may be seen in FIGS. 1 and 2, the sealing elements initially havevolumes (cross-sectional areas) less than the volumes or voids(cross-sectional areas) of their respective grooves. Because of thisvolume-void relation, the elements are capable ofbeing confined withintheir grooves and, as will be developed, this confinement is maintainedat all times during installation and use. This important feature ofthe'seal of the invention enables it to effectively use plastics havingno appreciable resilience, but other desirable properties, as a sealingmaterial.

It is advantageous from a cost standpoint that the elements 14a and bbeformed as flat bands, as shown in the drawing. in particular, thisenables them to be stamped in any desired overall shape, circular orotherwise, from flat sheet material. ln this connection, it may bedesirable to shape the elements 14a and b in such a way as to furtherenhance sealing and, when so shaped, theymay even initially project fromtheir respective grooves 22a and b. The sealing elements 14a and bembodied in the seal it) initially are narrower in width than therespective grooves 22a and b and herein are of approximately the samethickness as the initial depth of the grooves, preferably havingthicknesses slightly less than such initial depth. However, in aninstalled condition, as shown in FIG. 4, the elements span the entirewidths oftheir grooves, which are several times wider than their depth,and thereby exert sealing pressure over a substantial area. As a result,the seal It is especially adapted to accommodate surface irregularitieson the parts to be sealed,

The seal is intended to be installed between a pair of mating flanges,such as flanges 36 and 38, illustrated in FIGS. 3 and 4 with planarsurfaces. Such flanges might, for example, be found in a pipeline systemand are capable of being forceably brought together into sealingrelationship by bolts 40.

As the flanges 36 and 38 are brought together with the sealtherebetween, the opposing flange faces first contact the resistibledeformable ridges l8 and to confine the elements 14a and b within theirgrooves 22a and b. As further force is applied, the ridges flatten outand, in the caseof the illustrative embodiment, enable the sealingelements to contact their respective flange faces. The seal 10 is shownat this stage ofinstallation in FIG. 3.

As is apparent from FIGS. 2 and 3, this flattening of the ridges 18 and20 results in the voids of the grooves 22a and b being progressivelyreduced. As this occurs, the elements 14a and b deform laterally andbegin to fill the voids of the grooves.

This progressive sizing of the grooves 22a and b to the elements 14a andb continues as further force is applied to the flanges 36 and 38. Whenthe grooves are substantially filled, as in FIG. 4, greatly increasedresistance to further flattening is encountered. This follows from thefact that the sealing elements are formed of an incompressible material.By virtue of this material being confined within the grooves, cold flowis precluded, yet the sealing elements 14a and b bear a portion of theload applied by the flanges 36 and 38. Installation is thus completedand high-pressure sealing is achieved.

Since the grooves 22a and b afforded by the retainer 12 arevolumetrically sized to the sealing elements 14a and h duringinstallation of the seal, it will be appreciated that there is no needto hold the parts to close tolerances during manufacture. On thecontrary, the void of each groove need only be larger than the volume ofits corresponding element. Then, during installation, the groove void isprogressively reduced until it substantially equals the volume of itselement. This is an important feature of the seal of the invention andenables it to be mass produced at low cost, yet to achieve effectivesealing in high pressure applications.

Assuming that, as is desired, the ridges have some springbackcapability, the retainer is, in effect, preloaded. The ridges 28 and 18as well as the sealing elements 14a and b, respond to considerableflange separation to maintain confinement and effective sealing.

While the seal it) has been described as a two-sided seal for usebetween a pair of mating parts, it is to be understood that it mightalso be constructed for sealing against a single surface. in such case,the retainer member is shaped to provide only one groove and it issimply welded or otherwise secured on the side opposite the groove to acover for a container or the like. In such instance, a single sealingelement is provided.

In some applications it may be desirable for various reasons, includingespecially good resistance to caustic chemicals and ability to withstandhigh temperatures, to employ as the sealing element materials which haveno appreciable resilience. in this embodiment, the memory of the sealingmaterial cannot be relied on to enhance sealing. Typical of thesematerials are the fluorocarbon plastics. A seal 59 with deformablesealing elements 52a and b formed of such a material is illustrated inFIG. 5. The elements 52a and b initially span the entire widths of theirrespective grooves 22a and b.

Installation of the seal 54) of FIG. 5 takes place in the same manner aspreviously described. However, in this instance, there is no contactbetween the sealing elements 52a and b and the surfaces of the flanges36 and 38 until just prior to completion of the installation procedure.In other words, the ridges l8 and 20 must approach their finalflattening before such contact takes place. In the installed condition,the seal 50 has the appearance of that illustrated in FIGS. l and 2 andwould be as shown in FIG. 4.

Still another seal 60 constructed in accordance with the invention isillustrated in FIG. 6 and in a fully installed condition in FIG. 7. Theseal 6!) differs from the seal lit previously describedonly with regardto the construction of its retainer The ridges 64 and 66 are formedseparately from the web 68 and are here shown as secured to the oppositefaces of the latter. Each of the ridges 64 and 66 has, in cross section,a pair of web-engaging sections 70 integrally ,joined by a C-shapedsection 72 forming a loop.

The ridges 64 and 66 flatten out during installation, as illustrated inFIG. 7, and as with the previous embodiments, the voids of the grooves22a and b are progressively reduced until they are substantially equalto the volumes of the respective sealing elements 14a and b. Confinementof the sealing elements is thus achieved by the ridges 64 and 66 andeffective, high-pressure sealing results.

While certain embodiments of the invention have been illustrated anddescribed in detail, it will be understood that this was only by way ofexample and that various changes in the shapes, relative sizes andarrangements of the parts may be made without departing from the spiritand scope of the invention.

lclaim:

l. A seal comprising:

a ringlike sheet metal retainer having a central, generally planar,annular web and two sets of spaced, sheet metal ridge means 'on oppositesides of said retainer extending along and connected to both edges ofsaid web to cooperate with said web in defining oppositely openinggrooves of preselected initial cross-sectional areas in the oppositesides of said retainer;

said ridge means being resistibly deformable in response to clamping ofsaid retainer between two parts to be sealed and operable in response toclamping force on said ridge means to reduce the cross-sectional areasof the associated grooves progressively from said initial areas tolesser areas; and

two deformable sealing elements disposed in said grooves between theassociated ridge means in substantially backto-back relation and havingcross-sectional areas less than said initial areas and substantiallyequal to said lesser areas, whereby deformation of said ridge means toreduce said grooves to said lesser areas causes said sealing elements tosubstantially fill said grooves and be pressed into continuous sealingengagementwith the parts to be sealed as an incident to clamping of theseal between the parts.

2. A seal as defined in'claim 1, wherein said retainer and said ridgemeans are thin sheet metal and define shallow grooves several timeswider than the depths of the grooves, and said sealing elements are thinand flat annular bands of said deformable material having edges adjacentsaid ridge means, flat bottom sides against said web, and flat sealingsides facing out of said grooves for engagement with the parts to besealed.

3. A seal as defined in claim 2, wherein said bands are of approximatelythe same thickness as the initial depths of said grooves.

4. A seal as defined in claim 3, wherein the thickness of said bands isless than the initial depth of said grooves.

5. Aseal comprising:

a ringlike sheet metal retainer having a center hole and a generallyplanar annular web extending around said hole, said web havingoppositely facing substantially flat sides, and two sets of sheet metalridges integral with said web deformed in opposite directions from theplane of the web along the edges of the web to cooperate with the latterin defining two oppositely opening and substantially back-to-backannular grooves in the opposite sides of said retainer, each of saidgrooves having a preselected initial cross-sectional area and a widthseveral times greater than the depth of the groove; and

two sealing elements in the form of flat annular bands of deformablematerial having thicknesses approximately equal to said depths andcross-sectional areas less than said initial areas, and being disposedin said grooves with the edges of the elements adjacent said ridges,said ridges .being deformable under clamping forces tending to flattensaid retainer and being shaped to reduce the said initial area to alesser area during deformation thereby to conform the volume of eachgroove substantially to the volume of the sealing element therein duringclamping of the seal between two parts to be sealed, and to press saidsealing elements against the parts across the full widths of thegrooves. 1 A seal comprising:

a ringlike retainer including an annular web having a surface on oneside adapted to be disposed in opposed relation with a part to besealed, and spaced ridge means on said one side-of said retainerextending along and connected to opposite edges of said web andcooperating therewith in defining a groove of preselected initialcrosssectional area on said one side;

said ridge means being resistibly deformable in response to clamping ofsaid retainer with a normal sealing force against the part to be sealedand operable during deformation to reduce the area of said grooveprogressively from said initial area to a lesser cross-sectional area;and a deformable sealing element disposed in said groove between saidridge means and against said web, said sealing element having across-sectional area less than said initial area and substantially equalto said lesser area to fit between said ridge means and be disposedfully within said groove prior to deformation of said ridge meanswhereby clamping of said retainer against the part to be sealed deformssaid ridge means to reduce the cross-sectional area of said groovesubstantially to the area of said sealing element to urge the latterinto continuous sealing engagement with the part as an incident to suchclamping. 7. A seal as in claim 6, wherein said retainer is formed ofthin sheet material and said ridge means are ridges composed of similarsheet material secured to the edges of said web.

8. A seal as in claim 6, wherein said web and said ridge means arecomposed of thin sheet metal and said sealing element is a flat band ofdeformable material thinner than the initial depth of said groove to bedeformed away from said web and into sealing engagement with said onepart as said ridge means reduce the width of said groove during suchdeformation.

9. A seal as in claim 7, wherein said web is generally planar and saidridge means are formed integrally with said web and offset from theplane thereof.

10. A seal as in claim 7, wherein said web is generally planar and saidridge means are separate parts of similar sheet material attached to theedges of said web.

11. A seal as in claim 6, wherein said retainer has second re sistablydeformable ridge means on the opposite side thereof defining a secondoppositely opening groove and a second deformable sealing elementdisposed in said second groove to seal in a similar manner.

[2. A seal as in claim 11, wherein said retainer is composed of thinsheet metal and said web is a substantially planar ringlike element,said ridge means being hollow loops of sheet metal extending along theedges of said web and each forming two ridges extending in oppositedirections from one edge of said web to form corresponding sides of saidgrooves.

13. A seal as in claim 12, wherein said loops are integral with saidweb.

14. A seal as in claim 12, wherein said loops are separate partsattached to the edges of said web.

15. A sea] as in claim 11, wherein said web is a generally, planarringlike element and said grooves are continuous and in substantiallyback-to-back relation, said sealing elements comprising flat continuousbands of said deformable material having edges adjacent said ridge meansand substantially flat surfaces for sealing engagement across the fullwidths of said grooves.

16. A seal as in claim 15, wherein the thicknesses of said sealingelements are less than the initial depths of said grooves.

17. A seal as in claim 15, wherein said retainer and said ridges arecomposed of thin sheet metal having a resistance to deformation greaterthan the resistance of said deformable material.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION P tent NO-3,542,382 Dated November 24, 1970 Inventor-(s) Foster M. Hagmann It iscertified that error appears in the above-identified patent and thatsaid Letters Patent are hereby corrected as shown below:

In the Summary of the Invention:

Column 1, line 61, before "ridges" insert -means forming-.

line 62, before "ridges" delete "means forming".

line 71, delete "resistible" and insert therefor .-res'istibly-.

In the Description of Preferred Embodiment:

Column 4, line 7, delete "ridges 2.8 and 18" and insert therefor -ridgesl8 and 20- Signed and sealed this 20th day of July 1971.

(SEAL) Attest:

EDWARD M.F'LETGHER,JR. WILLIAM E. SCHUYLER, JR, LAttesting OfficerCommissioner of Patents

